Abstract：
Legumes are ecologically and economically important plants that contribute to nutrient cycling and agricultural sustainability, features tied to their intimate symbiosis with nitrogen-fixing rhizobia. Rhizobia vary dramatically in quality, ranging from highly growth-promoting to non-beneficial; therefore, legumes must optimize their symbiosis with rhizobia through host mechanisms that select for beneficial rhizobia and limit losses to non-beneficial strains. In this Perspective, we examine the considerable scientific progress made in decoding host control over rhizobia, empirically examining both molecular and cellular mechanisms and their effects on rhizobia symbiosis and its benefits. We consider pre-infection controls, which require the production and detection of precise molecular signals by the legume to attract and select for compatible rhizobia strains. We also discuss post-infection mechanisms that leverage the nodule-level and cell-level compartmentalization of symbionts to enable host control over rhizobia development and proliferation in planta. These layers of host control each contribute to legume fitness by directing host resources towards a narrowing subset of more-beneficial rhizobia.
摘要：
豆类是生态和经济上重要的植物，有助于营养循环和农业可持续性。与固氮根瘤菌紧密共生的特征。根瘤菌的质量差异很大，从高度促进增长到非有益的；因此，豆科植物必须通过选择有益根瘤菌并将损失限制在非有益菌株的宿主机制来优化与根瘤菌的共生关系。从这个角度来看,我们研究了在根瘤菌的宿主控制解码方面取得的相当大的科学进展，实证研究分子和细胞机制及其对根瘤菌共生的影响及其好处。我们考虑感染前控制，这需要豆科植物产生和检测精确的分子信号，以吸引和选择相容的根瘤菌菌株。我们还讨论了感染后的机制，这些机制利用共生体的结节水平和细胞水平的区室化来实现宿主对植物根瘤菌发育和增殖的控制。这些寄主控制层通过将寄主资源引向更有益的根瘤菌的缩小子集，每个都有助于豆科植物的适应性。
